Conventional X-Y mechanical stage adjustment apparatus for microscopes, cameras and the like includes the lens system mounted in a framework and a transversely mounted adjusting mechanism to focus the lens system on the object to be observed or photographed. A slide or specimen is mounted on the upper of two transversely movable plates which form part of the stage. After the lens system is focused on the slide, the transversely adjustable plates move the slide as needed to allow the operator to observe or photograph any area of the slide which are of interest.
Numerous systems have used a rack and pinion or gear system to move the lens system and mechanical stage to the proper focus and transverse adjustment. The problem is that a gear system inherently includes a frictional relationship, and a backlash due to material stress is inherent. Such backlash can make the best adjustment a difficult chore for the operator.
An example of an early focusing mechanism is in U.S. Pat. No. 1,120,014 showing a rack and pinion operation including gears as a mechanism for adjusting the focus of a lens system.
U.S. Pat. No. 1,521,067 is a modification of a lens adjusting system involving overlapping offset bands of woven material used to translate the lens system into the desired focus.
U.S. Pat. No. 1,576,340 shows a transverse offset mechanism for a lens system involving rollers riding on a rail and engaging alternate rollers to swing the lens system focus up and down or to one side or the other.
U.S. Pat. No. 3,768,885 involves a microscope. For focus adjustment a mechanical linkage and a rotatable cam are combined with a gear train. The whole system is much more complicated than necessary.
U.S. Pat. No. 4,204,732 describes adjusting the focus of a lens system by the use of gears. The inherent backlash problem is well known and undesirable.
U.S. Pat. No. 4,591,245 discloses adjusting the focus of a lens system using a threaded rod combined with a cam or lever system to move the lens system. Threads serve essentially the same function as gears in the above described patents and do not eliminate the undesirable backlash.
A column in the May, 1986 journal, Sky & Telescope, at pages 511-513 describes a focusing apparatus involving a lens mounted in a tube. A flat area on the tube exterior is aligned with a rubber tube surrounding a focusing shaft. Rotation of the shaft moves the tube to the desired focus location.
Another column in the January, 1987 journal, pages 95-96 describes a similar focusing technique, but in the latter case a rubber strip is adhesively bonded to the tube in place of the flat area described in the May, 1986 column.
An article from the journal, Machine Design, of Dec. 21, 1967 describes the dynamic features of a flexible band threaded in S-shaped configuration around two rollers and anchored to a pair of plates. The plates are aligned in parallel with each other and perpendicular to the axes of the rollers. The initial tension of the band is sufficient to capture the rollers for non-slip movement thereof.
In some apparatus for adjusting the X-Y axes of the mechanical stage the finger adjustment knobs are along side one edge of each plate to be adjusted and in other devices the knobs are mounted concentrically. The particular location of adjustment knobs is optional in this invention and any physical location is within the inventive concept.